Once the days have passed, you can go to the small claims court and file for an unlawful detainer.

You should run that report independently, and also search for legal actions (evictions & unlawful detainers), and any criminal convictions.As a former property manager to a few large apartment communities, I tell you that 90% of problems come from poor tenant screening.  

If you really don’t want them there any more, and they truly refuse to leave, you’d be forced to evict them (unlawful detainer action) to remove them. 

In Maryland the case you file is called "Wrongful Detainer" PA may have a different name for it.

Since your previous tenant has abandoned the property and this new person is a complete stranger, with no lease, it sounds like an unlawful detainer case which I've found is quicker than an eviction.

The complaints grew and I had no choice but to file an "Unlawful Detainer" eviction.Since then things have become worse.

If she doesn't leave, then evict her for unlawful detainer.

There is plenty of possibilities, but not all of them are accepted by banks.You could buy the company which is holding the building(s) if they're not detained personallyYou could create a company which the seller still hold a certain % by the time you give him his full amount of moneyPut him in 2nd rank mortgage while you repay his selling balance.

Have you ever been evicted (unlawful detainer)?"

All of those conditions must be true for a lease to be bonafide in a foreclosure action and subsequent unlawful detainer.